A thunderstorm occurs in Jump city with lots of thunder and lightning but these are the two teenage brothers Thunder and Lightning who are causing the storm. They roam the town looking for fun. Unfortunately, their idea of fun is wrecking everything in sight, regardless of those being injured in the process. At Titans Tower, Beast Boy attempts a prank on Cyborg, only to accidentally pull the prank on Starfire instead. Beast Boy is at a loss of words, and Starfire starts to ignore him after she insulted him by calling him a "Klorbag Varblenelk". Robin reports of an incident on the bridge, where the Titans rush to the scene.
Thunder and Lightning are wreaking havoc on the bridge, destroying cars and alarming the people. The Titans fight them and during the fight Beast Boy asks Thunder why he is doing this. Thunder claims that it is fun, but his expression shows his uncertainty. The brothers retreat after they are nearly overwhelmed by the Titans. Robin suggests they look everywhere for the two brothers. Unfortunately for Beast Boy, he is paired up with Starfire, who ignores all his jokes and apologies. Beast Boy inquires why he cannot go with Cyborg instead, to which Robin points out Cyborg's inability of flight. Their awkward silence is broken when Thunder and Lightning arrive on the scene.
Starfire and Beast Boy both have an intense fight against the two brothers, during which Beast Boy tries to persuade Thunder to stop all his violence. Thunder is about to reply when an old man arrives on the scene with a small explosive device. He destroys the nearby statues and incapacitates Beast Boy and Starfire. The old man claims that he has nature-based powers as well and that he can help them in maintaining use for their powers. Beast Boy crawls out of the debris as a spider and desperately tries to dig through the debris to find Starfire. As he searches, he is finally overcome with guilt and apologies to Starfire for pulling the prank on her. Starfire walks up behind, and smiles at Beast Boy, who is overjoyed that she is unharmed. Beast Boy gets down on his knees and begs Starfire for forgiveness, to which she tells him he already has. The two teammates then reconcile and become friends again. Starfire then tells him that they need to stop the evil brothers, to which Beast Boy replies that he doesn't think they're evil, he thinks that they're just like him.
Meanwhile, on a hilltop overlooking Jump City, the old man tells Thunder and Lightning to set fire to some scarecrows. Lightning says there is no fun in doing that. The old man tells them to try. They use their respective powers to burn all the scarecrows. They ask for more targets when there are no more. The old man tells them that they have already done an excellent job and throws a disk into the sky. The burning scarecrows have their fires joined together by the power of the disk in a Mark of Scath and a gigantic fire monster emerges from the fires. The monster heads towards Jump City, content on destroying the city. The Titans intercept the monster and begin to fight it. They pull away all the trees around them, but the monster continues to burn, and continues to pick up speed.
Meanwhile, Robin has slipped away and reached the top of the hill where the old man is smiling down at the scene. Robin fights the old man, but is overpowered by him. Thunder and Lightning once again engage with the Titans, with Thunder having another confrontation with Beast Boy. Thunder tells Beast Boy to stand aside, but Beast Boy reasons with him and tells him the old man was wrong in that having powers made someone special, and it is how someone uses the powers that makes them special. This finally makes Thunder see the error of his ways and he intervenes with Lightning when he's about to attack Starfire. Lightning is angered by Thunder's betrayal and the two brothers get into a fight. Robin continues fighting the old man, but he is too powerful and Robin gets pinned against a tree. Lightning then manages to knock Thunder to the ground, and is about to finish him off, however Thunder asks Lightning whether he is still having fun. Lightning replies that he isn't, and Thunder tells him to observe the Titans who use their gifts to help others. Finally giving in, Lightning combines with Thunder to form rain, which they send down from the sky at the fire monster, extinguishing its flames. When the old man is about to kill Robin, a lightning strike hits the old man's staff, shocking him and releasing Robin at the same time. The old man's mask crumbles away, revealing Slade to be the old man all along. Robin glares angrily, recognizing his arch-enemy. Slade tells Robin that he had manipulated the powers of Thunder and Lightning so that he could create the fire monster. Slade drops down on his knees, telling Robin they will meet again, and with a swish of his cloak, disappears.
After the rain has stopped, a rainbow appears. On the other side of town, Cyborg asks Robin why Slade would want to destroy the city. Robin replies that he doesn't know, but he's going to find out. Meanwhile Beast Boy asks Starfire if he is forgiven. She says he is now a Milnip wooserlop, to which Beast Boy celebrates, before asking her if that's a good thing. Starfire only laughs as she flies away, with Beast Boy runs after her.